Question: An airplane has three sections: First Class (24 seats), Business Class ($25\%$ of the total number of seats) and Economy ($\frac{2}{3}$ of the total number of seats). How many seats does the plane have?
Suppose that the airplane has $s$ seats.  Then we have that $24 + 0.25 s + \frac{2}{3} s = s$.  Solving, we find that $s = \boxed{288}$.